NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 03:59 It is currently 25 Apr 2024, 03:59
Decision Tracker
My Rewards
New posts
New comers' posts

Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

a rectangular piece in cylinder

User avatar
S
dimri10
Manager
Manager
Joined: 16 May 2011
Posts: 240
Own Kudos [?]: 308 [0]
Given Kudos: 64
Concentration: Finance, Real Estate
GMAT Date: 12-27-2011
WE:Law (Law)
Send PM
GMAT ToolKit User
a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 01:35
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (00:01) correct 0% (00:00) wrong based on 3 sessions
Hide Show timer Statistics
a rectangular piece of cardboard measuring 12 by 16 is folded into a cylinder akong one of its sides, what's the maximal volume of the cylinder:

1. 576/pi

2. 768/pi

3. 861/pi

4. 192pi

5.784pi

i do not have the OA.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
jamifahad
Senior Manager
Senior Manager
Joined: 03 Mar 2010
Posts: 259
Own Kudos [?]: 1371 [0]
Given Kudos: 22
Schools: Simon '16 (M$)
Send PM
Re: a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 02:04
V=pi r^2 h
Max volume when r is max.
hence r=8 (folded such that side 16 forms diameter)
V=pi 8^2 * 12
=768pi

OA B.
User avatar
S
dimri10
Manager
Manager
Joined: 16 May 2011
Posts: 240
Own Kudos [?]: 308 [0]
Given Kudos: 64
Concentration: Finance, Real Estate
GMAT Date: 12-27-2011
WE:Law (Law)
Send PM
GMAT ToolKit User
Re: a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 02:13
that's tha answer i got, but the answers declare: 766 divided by pi
User avatar
B
subhashghosh
Retired Moderator
Joined: 16 Nov 2010
Posts: 909
Own Kudos [?]: 1173 [0]
Given Kudos: 43
Location: United States (IN)
Concentration: Strategy, Technology
Send PM
Reviews Badge
Re: a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 02:26
There are two ways of doig this :

1 in which circumference = 2*pi*r = 12 => r = 6/pi and height = 16 => volume = pi * 36/pi^2 * 16 = 576/pi

2 in which circumference = 2*pi*r = 16 => r = 8/pi and height = 12 => volume = pi * 64/pi^2 * 12 = 768/pi

Answer - B
User avatar
S
dimri10
Manager
Manager
Joined: 16 May 2011
Posts: 240
Own Kudos [?]: 308 [0]
Given Kudos: 64
Concentration: Finance, Real Estate
GMAT Date: 12-27-2011
WE:Law (Law)
Send PM
GMAT ToolKit User
Re: a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 02:35
subhashghosh wrote:
There are two ways of doig this :

1 in which circumference = 2*pi*r = 12 => r = 6/pi and height = 16 => volume = pi * 36/pi^2 * 16 = 576/pi

2 in which circumference = 2*pi*r = 16 => r = 8/pi and height = 12 => volume = pi * 64/pi^2 * 12 = 768/pi

Answer - B



the first step is important:

concluding that 12 or 16 are the circumference was based on what premise?
the Q was saying that the measure of the box were 12/16 or am i missing somthing?
User avatar
B
subhashghosh
Retired Moderator
Joined: 16 Nov 2010
Posts: 909
Own Kudos [?]: 1173 [1]
Given Kudos: 43
Location: United States (IN)
Concentration: Strategy, Technology
Send PM
Reviews Badge
Re: a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 03:03
1
Kudos
It's like this :
When you roll a piece of paper into a cylinder, the length or breadth becomes a circle of the base. Now the perimeter of this circle is equal to the length of the side, and the perimeter of a circle = circumference of a circle. You can try to roll a paper and you'll get the idea.
User avatar
S
dimri10
Manager
Manager
Joined: 16 May 2011
Posts: 240
Own Kudos [?]: 308 [0]
Given Kudos: 64
Concentration: Finance, Real Estate
GMAT Date: 12-27-2011
WE:Law (Law)
Send PM
GMAT ToolKit User
Re: a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 03:31
THANK'S. i imagined it quite differently. you treated that like a roll and i treated it as sitting on tha radius. that's great
User avatar
B
subhashghosh
Retired Moderator
Joined: 16 Nov 2010
Posts: 909
Own Kudos [?]: 1173 [0]
Given Kudos: 43
Location: United States (IN)
Concentration: Strategy, Technology
Send PM
Reviews Badge
Re: a rectangular piece in cylinder [#permalink] New post   13 Jun 2011, 03:36
Yup, as I said, trying to do this in real life can give valuable insight into how the 3-D figures look like. Glad to help :)
User avatar
puneetj
Manager
Manager
Joined: 08 Sep 2010
Posts: 70
Own Kudos [?]: 84 [0]
Given Kudos: 18
Send PM
Re: a rectangular piece in cylinder [#permalink] New post   14 Jun 2011, 19:16
v= pi*r^2*h
use r=6, h = 16 and calculate
use r= 8 and h = 12 and calculate

B...



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: a rectangular piece in cylinder [#permalink]
14 Jun 2011, 19:16
Moderators:
Bunuel
Math Expert
92912 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions